In the process of machining, the effluent discharged includes cooling fluid, organic cleaning fluid, spray paint wastewater and electro - spark working fluid and other wastewater. The amount of waste water is small but the concentration of organic matter is high. Among them, CODCr of cooling liquid reaches up to 50000 ~ 300000mg/L. If it is discharged directly, it will cause serious pollution to the environment.
At present, the high concentration and heavily emulsified oily wastewater discharged from the mechanical processing in China has not been treated well. The main reason is that with the continuous improvement of technology, the stability of emulsion is higher and higher, and the demulsifying is more and more hard. This kind of waste water has complex components, poor biodegradability and certain toxicity.Technologicalprocess